I have a wet mount transducer, a foam block with a hole cut through for the 'ducer, and glued onto the hull. Just put a little water into the cavity and push the transducer in. Holds it nice and sound. This is an especially good method if you might want to remove the unit for other uses. Another advantage is that I get a fairly good temperature reading at night or on cloudy days. On sunny days the inside of the hull heats up too much and throws the reading off.

I did the foam block and the cut-out for the transducer, but I used Lexel to glue my transducer down ....The foam block is just to protect the transducer from anything that may shift around under my P.A. ...Jim

I used a "Liberator" mount with transducer arm from Mad Frog kayak gear, the fishfinder, all wiring, and transducer is installed on the mount. the small 12 volt 5 amp battery is in a waterproof plastic box sourced from Walmart. the liberator mount is mounted to a Scotty fishfinder mount which in turn is mounted to a clamp on Scotty mount on the side rail. no holes had to be drilled anywhere and everything can be removed easily and quickly and no need to goop your transducer in the hull. http://www.madfroggear.com/liberator/liberator.html

My wet mount install cost was $14 for the 4" pvc threaded pipe end and 4" rubber cap. The rubber cap is 1/2 thick. I shaved the pvc piece to fit the left section of the hull next to the tackle area and marine gooped it in place.

The transducer was screwed into the rubber cap and the wire opening was sealed with marine goop.

After everything had dried completely I filled the new pvc well with 18 oz of water and slowly put the cap/transducer on the pvc pipe. Water spilled out a bit as the transducer went in. Tightened the SS clamp as was good to go.

This setup is +80% more sensitive than when I siliconed the transducer directly to the hull. I had my sensitivity setting on 18 and reduced it to 2.